Pen



FIG. 1 is a side, top, perspective view of a pen showing our new design;

FIG. 2 is a left side view thereof, the right side view being a mirror image of the left side view;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a front view thereof; and,

FIG. 6 is a rear view thereof.

The broken lines showing the clip in FIGS. 1, 2, 3, 5 and 6 are included for the purpose of showing a portion of the pen that forms no part of the claimed design. 

CLAIM The ornamental design for pen, as shown and described. 